I added some stuff you suggested me:-Sounds (Thanks to BurntPizza, http://www.bfxr.net/ is a very cool tool)-the small enemy has now a shorter range, and shoots less precisely-the dificulty increases now every 15 seconds instead of 10, so it should be a bit easier now-some upgrades are more expensive-savegames and highscore are now encrypted (Thanks to Gibbo3771, Base64 was easy to use and works great)

Aww yeah, this is pretty damn fun, that barrage of arcade-y audio goodness is great. Only sound effect that didn't seem to fit was the menu button 'click', to me those are usually 'two syllables' if that makes any sense.

First time I got the 'auto shotgun' effect after deploying a special was unexpected and epic. You're doing it right.

A few more things I noticed this time around:

Perhaps a volume control somewhere, or just a mute button? Also the music should probably stop if the game is minimized.Be able to hold down up or down to scroll through letters when entering your nameMaybe not so much aimbot on the red ships? At least not at first, the difficulty suddenly goes way up when those guys show up, doesn't feel smooth to me. Who knows.

Just wanted to say that I've been playing around with this for the past two days. Maybe 45 minutes total play time and I really enjoyed it. And like others have mentioned, I think it gets too hard too fast, but other than that--this is great!